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Abstract:

There are provided a conductive paste for internal electrodes, a
multilayer ceramic electronic component including the same, and a method
of manufacturing the same. The conductive paste for internal electrodes
including: a nickel (Ni) powder; a nickel oxide (NiO) powder having a
content of 5.0 to 15.0 parts by weight based on 100 parts by weight of
the nickel powder; and an organic vehicle.

Claims:

1. A conductive paste for internal electrodes comprising: a nickel (Ni)
powder; a nickel oxide (NiO) powder having a content of 5.0 to 15.0 parts
by weight based on 100 parts by weight of the nickel powder; and an
organic vehicle.

2. The conductive paste of claim 1, wherein the nickel powder has an
average particle size of 80 nm to 200 nm.

3. The conductive paste of claim 1, wherein the nickel oxide powder has
an average particle size of 10 nm to 50 nm.

4. The conductive paste of claim 1, wherein the organic vehicle includes
an ethyl cellulose-based binder and terpineol.

5. A multilayer ceramic electronic component comprising: a ceramic body
in which a plurality of dielectric layers are stacked; and a plurality of
internal electrodes formed on at least one surfaces of the plurality of
dielectric layers, wherein the plurality of internal electrodes are
formed of a conductive paste including a nickel (Ni) powder, a nickel
oxide (NiO) powder having a content of 5.0 to 15.0 parts by weight based
on 100 parts by weight of the nickel powder, and an organic vehicle.

6. The multilayer ceramic electronic component of claim 5, wherein the
nickel powder has an average particle size of 80 nm to 200 nm.

7. The multilayer ceramic electronic component of claim 5, wherein the
nickel oxide powder has an average particle size of 10 nm to 50 nm.

8. The multilayer ceramic electronic component of claim 5, wherein the
organic vehicle includes an ethyl cellulose-based binder and terpineol.

9. The multilayer ceramic electronic component of claim 5, wherein a
shrinkage initiation temperature of the internal electrodes is lower than
that of the ceramic body, the shrinkage initiation temperature is
700.degree. C. or above.

10. The multilayer ceramic electronic component of claim 5, further
comprising external electrodes formed on both end surfaces of the ceramic
body and electrically connected to the internal electrodes.

11. A method of manufacturing a multilayer ceramic electronic component,
the method comprising: forming first and second internal electrodes by
applying a conductive paste including a nickel (Ni) powder, a nickel
oxide (NiO) powder having a content of 5.0 to 15.0 parts by weight based
on 100 parts by weight of the nickel powder, and an organic vehicle to at
least one surfaces of first and second ceramic sheets, so as to be
exposed through both end surfaces of the first and second ceramic sheets,
respectively; forming a laminate by alternately stacking the plurality of
first and second ceramic sheets having the first and second internal
electrodes formed thereon; forming a ceramic body by sintering the
laminate; and forming first and second external electrodes on both end
surfaces of the ceramic body so as to cover surfaces on which the first
and second internal electrodes are exposed.

12. The method of claim 11, wherein in the forming of the first and
second internal electrodes, the first and second internal electrodes are
alternately exposed through both end surfaces of the laminate when the
first and second ceramic sheets are alternately stacked.

Description:

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the priority of Korean Patent Application
No. 10-2012-0091667 filed on Aug. 22, 2012, in the Korean Intellectual
Property Office, the disclosure of which is incorporated herein by
reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to a conductive paste for internal
electrodes, a multilayer ceramic electronic component using the same, and
a method of manufacturing the same.

[0004] 2. Description of the Related Art

[0005] As electronic components using a ceramic material, there may be
provided a capacitor, an inductor, a piezoelectric element, a varistor, a
thermistor, and the like.

[0006] Among these, a multilayer ceramic capacitor (MLCC), a condenser
having a chip shape, has advantages such as compactness, high
capacitance, and ease of mounting, and may be easily installed in printed
circuit boards of various electronic products such as personal digital
assistants (PDAs), cellular phones, and the like, to perform an important
role in charging electricity therein and discharging electricity
therefrom. MLCCs have various sizes and stack structures according to
intended use and desired capacitance thereof.

[0007] Recently, in accordance with the trend for small, slimmed
electronic products, a multilayer ceramic capacitor, an essential passive
component in electronic products, has also been required to have a
subminiaturized size and super high capacitance.

[0008] Therefore, a multilayer ceramic capacitor in which a dielectric
layer and internal electrodes are thinned for the subminiaturized size,
and increasing amounts of dielectric layers and internal electrode layers
have been stacked in order to realize super high capacitance has been
manufactured.

[0009] In the multilayer ceramic capacitor, barium titanate (BaTiO3)
is generally used as a material for dielectric layers, and nickel is
commonly used as a material for internal electrodes. Here, it is
necessary to use particulate barium titanate and particulate nickel
powder having high crystallinity for a product having a subminiaturized
size and high capacitance.

[0010] The multilayer ceramic capacitor may be manufactured by stacking
layers of internal electrode formed on ceramic sheets and performing a
co-firing process at a temperature of 1000° C. to 1200° C.
for densification of the ceramic sheets. However, a particulate nickel
powder may be over-fired, resulting in particle-growth, such that the
thickness of the internal electrode may be increased, causing a
limitation in producing a small, slimmed product. In addition, since a
large gap may be formed between the internal electrodes to cause a
disconnection phenomenon in which the internal electrodes are
disconnected from each other, internal electrode connectivity may be
deteriorated, and capacitance may be decreased.

[0011] In addition, a nickel powder particle may have a large surface
area, high activity, and a significantly low sintering initiation
temperature. In particular, in the case of performing the sintering
process under a non-oxidation atmosphere in order to prevent the
oxidation of nickel, the internal electrode formed of nickel is initially
sintered and shrunk at a low temperature of 400° C. or less;
however, the ceramic sheet having a relatively higher sintering
temperature is not sintered and shrunk.

[0012] Therefore, at the time of the sintering process, shrinkage
behaviors of the ceramic sheet and the internal electrode may be
different, to thereby generate a relatively large amount of stress in the
multilayer ceramic capacitor, such that structural defects such as
delamination, cracking, and the like, may be generated in products,
leading to deteriorated productivity in a multilayer ceramic capacitor
manufacturing process.

[0013] In order to solve the problem, nickel powder particle surfaces may
be coated with an oxide.

[0014] However, in this case, the oxide may react with the ceramic of the
dielectric layer to obtain an additional effect in changing ceramic
characteristics. In addition, when a coating layer is formed around the
nickel particles which are not completely dispersed but are agglomerated,
since shrinkage is initiated in the nickel particle present in the
coating layer at an original low temperature, the coating layer may be
destroyed and the sintering process may rapidly progress, such that the
oxide may be extruded to the outside of a sintered body. As a result, an
effect of suppressing the sintering of the nickel may not be sufficiently
obtained.

SUMMARY OF THE INVENTION

[0015] An aspect of the present invention provides a conductive paste for
internal electrodes for manufacturing a multilayer ceramic electronic
component having excellent reliability, a multilayer ceramic electronic
component using the same, and a method of manufacturing the same.

[0016] According to an aspect of the present invention, there is provided
a conductive paste for internal electrodes including: a nickel (Ni)
powder; a nickel oxide (NiO) powder having a content of 5.0 to 15.0 parts
by weight based on 100 parts by weight of the nickel powder; and an
organic vehicle.

[0017] The nickel powder may have an average particle size of 80 nm to 200
nm.

[0018] The nickel oxide powder may have an average particle size of 10 nm
to 50 nm.

[0019] The organic vehicle may include an ethyl cellulose-based binder and
terpineol.

[0020] According to another aspect of the present invention, there is
provided a multilayer ceramic electronic component including: a ceramic
body in which a plurality of dielectric layers are stacked; and a
plurality of internal electrodes formed on at least one surfaces of the
plurality of dielectric layers, wherein the plurality of internal
electrodes are formed of a conductive paste including a nickel (Ni)
powder, a nickel oxide (NiO) powder having a content of 5.0 to 15.0 parts
by weight based on 100 parts by weight of the nickel powder, and an
organic vehicle.

[0021] A shrinkage initiation temperature of the internal electrodes may
be lower than that of the ceramic body, and the shrinkage initiation
temperature may be 700° C. or above.

[0022] The multilayer ceramic electronic component may further include
external electrodes formed on both end surfaces of the ceramic body and
electrically connected to the internal electrodes.

[0023] According to another aspect of the present invention, there is
provided a method of manufacturing a multilayer ceramic electronic
component, the method including: forming first and second internal
electrodes by applying a conductive paste including a nickel (Ni) powder,
a nickel oxide (NiO) powder having a content of 5.0 to 15.0 parts by
weight based on 100 parts by weight of the nickel powder, and an organic
vehicle to at least one surfaces of first and second ceramic sheets, so
as to be exposed through both end surfaces of the first and second
ceramic sheets, respectively; forming a laminate by alternately stacking
the plurality of first and second ceramic sheets having the first and
second internal electrodes formed thereon; forming a ceramic body by
sintering the laminate; and forming first and second external electrodes
on both end surfaces of the ceramic body so as to cover surfaces on which
the first and second internal electrodes are exposed.

[0024] In the forming of the first and second internal electrodes, the
first and second internal electrodes may be alternately exposed through
both end surfaces of the laminate when the first and second ceramic
sheets are alternately stacked.

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and other aspects, features and other advantages of the
present invention will be more clearly understood from the following
detailed description taken in conjunction with the accompanying drawings,
in which:

[0026]FIG. 1 is a perspective view schematically showing a multilayer
ceramic capacitor according to an embodiment of the present invention;

[0027]FIG. 2 is a cross-sectional view taken along line A-A' of FIG. 1;

[0028]FIG. 3 is a graph showing shrinkage behavior of a conductive paste
according to a content of nickel oxide;

[0029] FIG. 4A is a scanning electron microscope (SEM) image showing a
cross-section of an internal electrode formed of a conductive paste
including barium titanate of the related art; and

[0030]FIG. 4B is an SEM image showing a cross-section of an internal
electrode formed of a conductive paste including nickel oxide according
to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] Embodiments of the present invention will now be described in
detail with reference to the accompanying drawings.

[0032] The embodiments of the present invention may be modified in many
different forms and the scope of the invention should not be limited to
the embodiments set forth herein.

[0033] Rather, these embodiments are provided so that this disclosure will
be thorough and complete, and will fully convey the concept of the
invention to those skilled in the art.

[0034] In the drawings, the shapes, dimensions, or the like, of elements
may be exaggerated for clarity.

[0035] The present invention relates to a multilayer ceramic electronic
component. An example of the multilayer ceramic electronic component
according to an embodiment of the present invention includes a multilayer
ceramic capacitor, an inductor, a piezoelectric element, a varistor, a
chip resistor, a thermistor, and the like. Hereinafter, a multilayer
ceramic capacitor is described as an example of the multilayer ceramic
electronic component.

[0036] Referring to FIGS. 1 and 2, a multilayer ceramic capacitor 100
according to the present embodiment may include a ceramic body 110 in
which a plurality of dielectric layers 111 are stacked; and a plurality
of first and second internal electrodes 131 and 132 formed on at least
one surfaces of the plurality of dielectric layers 111.

[0037] Here, first and second external electrodes 121 and 122 may be
formed on both end surfaces of the ceramic body 110 to be electrically
connected to the first and second internal electrodes 131 and 132.

[0038] The ceramic body 110 may generally have a rectangular
parallelepiped shape, but is not specifically limited thereto.

[0039] In addition, the ceramic body 110 is not specifically limited in
dimensions. For example, the ceramic body 110 may have a size of 0.6
mm×0.3 mm, or the like, to allow a multilayer ceramic capacitor
having high capacitance of 1.0 μF or more, and more preferably, 22.5
μF or more to be manufactured.

[0040] The ceramic body 110 may include a dielectric cover layer (not
shown) having a predetermined thickness formed on an upper surface and a
lower surface thereof in a lamination direction.

[0041] A thickness of a single dielectric layer 111 contributing to
forming capacitance within the capacitor may be appropriately changed
according to a desired level of capacitance in the multilayer ceramic
capacitor.

[0042] In the present embodiment, a thickness of a single dielectric layer
111 after a firing process may be set to be 1.0 μm or less, and more
particularly, 0.01 to 1.0 μm; however, the present invention is not
limited thereto.

[0043] The dielectric layer 111 may include a ceramic powder, for example,
a BaTiO3-based ceramic powder, or the like. However, the present
invention is not limited thereto.

[0044] An example of the BaTiO3-based ceramic powder may include
(Ba1-xCax)TiO3, Ba(Ti1-yCay)O3,
(Ba1-xCax)(Ti1-yZry)O3, or
Ba(Ti1-yZry)O3, or the like, having Ca, Zr, or the like,
introduced in BaTiO3, but is not limited thereto.

[0045] The ceramic powder may have an average particle of 200 nm or less,
and more preferably, 80 nm to 100 nm, but the present invention is not
limited thereto.

[0046] In addition to the ceramic powder, a transition metal oxide or
carbide, a rare-earth element, a ceramic additive such as Mg, Al, or the
like, an organic solvent, a plasticizer, a binder, a dispersant, or the
like, may be selectively added to the dielectric layer 111.

[0047] The internal electrodes 131 and 132 may be printed on each ceramic
sheet forming the dielectric layer 111 by a screen printing method, a
gravure printing method, or the like.

[0048] Here, the internal electrodes 131 and 132 may be formed in the
ceramic body 111 having the dielectric layer 111 interposed therebetween,
through stacking and sintering processes.

[0049] In addition, the internal electrodes 131 and 132 may be formed as a
pair of a first internal electrode 131 and a second internal electrode
132 having different polarities, and in this case, the first internal
electrode 131 and the second internal electrode 132 may be disposed to
face each other in a lamination direction, having the dielectric layer
111 interposed therebetween.

[0050] The thickness of the internal electrodes 131 and 132 may be
appropriately determined according to use thereof, or the like, for
example, may be 1.0 μm or less, and more preferably, may be selected
within the range of 0.01 to 1.0 μm.

[0051] The internal electrodes 131 and 132 may be formed of a conductive
paste including a nickel (Ni) powder, and the conductive paste may
include a nickel oxide powder having a content of 5.0 to 15.0 parts by
weight based on 100 parts by weight of nickel powder, and an organic
vehicle.

[0052] Therefore, the nickel oxide powder and the organic vehicle are
included in the conductive paste, thereby increasing a shrinkage
initiation temperature of the internal electrodes 131 and 132. Here, the
shrinkage initiation temperature of the internal electrodes 131 and 132
may preferably be lower than that of the ceramic body 110, and the
minimum value thereof may more preferably be 700° C. or more.

[0053] Referring to FIG. 3, it may be appreciated that as an added amount
of nickel oxide is increased, the shrinkage initiation temperature is
also increased.

[0054] The reason that the shrinkage initiation temperature of the
conductive paste is increased is as follows. As the temperature is
increased, the nickel particles may be connected to each other and be
grown in order to decrease a large specific surface area thereof. During
the growth of the nickel particles, the nickel oxide added when the
nickel particles are grown to be connected to adjacent nickel particles
may be present between the nickel particles to prevent the nickel
particles from being grown, thereby decreasing the sintering initiation
temperature.

[0055] Since a melting point of nickel is 1455° C. and a melting
point of nickel oxide is 1955° C., about 500° C. higher
than that of nickel, it is expected that the nickel oxide delays the
shrinkage of nickel.

[0056] Meanwhile, the shrinkage initiation temperature according to a
content of nickel oxide is increased as the added amount of nickel oxide
is increased; however, an excessive amount of nickel oxide components may
remain in a portion of the internal electrodes 131 and 132 after the
sintering process and may be protruded from the internal electrodes 131
and 132 to the dielectric layer 111. Therefore, in the case in which the
content of nickel oxide is excessive, breakdown voltage (BDV) may be
decreased, and accordingly, there is a need to limit the amount thereof.

[0057] In addition, as the content of nickel oxide is increased, a change
in volume in a reduction process increases, to thereby deteriorate
electrode connectivity. Therefore, when the content of nickel oxide is
5.0 to 15.0 parts by weight, an effect of shrinkage delay is not
sufficient, such that the desired amount of added nickel oxide may be 5.0
to 15.0 parts by weight at the time of analyzing the shrinkage behavior
and the electrode connectivity.

[0058] The nickel powder included in the conductive paste may have an
average particle size of 80 nm to 200 nm. In the case in which the
average particle size of the nickel powder is less than 80 nm, it may be
difficult to control the shrinkage at the time of the sintering process,
and in the case in which the average particle size of the nickel powder
is more than 200 nm, it may be difficult to allow the internal electrodes
131 and 132 to have a thin film shape.

[0059] In addition, the nickel oxide powder included in the conductive
paste may have an average particle size of 10 to 50 nm.

[0060] In addition, the organic vehicle included in the conductive paste
may be an ethyl cellulose-based binder, terpineol as a solvent, or the
like. The ethyl cellulose-based binder may implement thixotropy,
adhesion, and phase stability. Terpineol has a high viscosity as a
solvent to thereby allow the conductive paste to be easily manufactured,
and has a high boiling point to thereby slow a drying rate thereof.
Therefore, terpineol may serve to be advantageous for a leveling process
after printing the conductive paste.

[0061] Distal ends of the internal electrodes 131 and 132 as described
above may be exposed through one end portion of the ceramic body 110. In
the present embodiment, the distal ends of the first and second internal
electrodes 131 and 132 in a length direction are shown to be alternately
exposed to both opposing end surfaces of the ceramic body 110.

[0062] However, the present invention is not limited thereto. If
necessary, the distal ends of the first and second internal electrodes
131 and 132 may be exposed through the same surface of the ceramic body
110, or may be exposed through two or more surfaces of the ceramic body
110, respectively, which may be changed in various structures.

[0063] The first and second external electrodes 121 and 122 may be formed
on both end surfaces of the ceramic body 110. The first and second
external electrodes 121 and 122 may be electrically connected to the
distal ends of the first and second internal electrodes 131 and 132
exposed to at least one surface of the ceramic body 110, respectively.

[0064] A conductive material included in the first and second external
electrodes 121 and 122 is not specifically limited. For example, a
conductive paste formed of a noble metal material such as palladium (Pd),
a palladium-silver (Pd--Ag) alloy, or the like, and at least one of
nickel (Ni) and copper (Cu) may be used.

[0065] In addition, the thickness of the external electrodes 121 and 122
may be appropriately determined according to use thereof, or the like,
may be 10 μm to 50 μm for example.

[0066] Hereinafter, an operation of the multilayer ceramic capacitor
according to an embodiment of the present invention will be described.

[0067] In general, in the conductive paste for internal electrodes, as an
average particle size of the nickel powder is decreased, a surface area
of the nickel powder is squared to increase surface energy of the nickel
powder, thereby lowering the shrinkage initiation temperature of the
nickel powder.

[0068] Therefore, in the case of forming the internal electrodes 131 and
132 using the conductive paste including the particulate nickel powder,
at the time of the sintering process in manufacturing the multilayer
ceramic capacitor 100, the sintering initiation temperature of the
internal electrodes 131 and 132 formed on the ceramic sheets is moved to
a low temperature by an increased amount of the particulate material.

[0069] Accordingly, before the ceramic sheet is shrunk, the sintering
process of the nickel powder included in the internal electrodes 131 and
132 is performed, such that delamination or cracking may be generated in
the dielectric layer 111, overfiring may be performed on the internal
electrodes 131 and 132. Therefore, since the metal components are
agglomerated in an unevenly distributed state, the internal electrodes
131 and 132 may have a disconnection portion to thereby deteriorate the
connectivity of the internal electrodes 131 and 132, and deteriorate the
capacitance and reliability thereof.

[0070] As a method for solving the problem, a particulate barium titanate
powder is added to the conductive paste for internal electrodes to
thereby move the shrinkage initiation temperature of the nickel particles
to a high temperature.

[0071] However, as shown in FIG. 4A, in the case in which the particulate
barium titanate powder is added to the conductive paste for internal
electrodes to form the internal electrodes, the cracking generated in the
dielectric layer may be partially controlled; however, the added
particulate barium titanate powder is permeated into the dielectric layer
during the sintering process to accelerate growth of particles of barium
titanate present in the dielectric layer. Therefore, breakdown voltage
(BDV) may be decreased and reliability may also be deteriorated.

[0072] Meanwhile, as shown in FIG. 4B, in the present embodiment, the
internal electrodes are formed by adding nano-scale nickel oxide to the
conductive paste for internal electrodes, instead of adding barium
titanate thereto.

[0073] In this case, the internal electrodes may be shrinkage-controlled
to be the same level as the case of adding barium titanate to the
conductive paste for internal electrodes. In addition, since there is no
phenomenon in the related art in which barium titanate is moved to the
dielectric layer, the BDV may not be decreased to prevent reliability
from being deteriorated.

[0074] As another method for solving the problem, in the case in which the
nickel particle is added to the conductive paste for internal electrodes,
two types of metal powder are additionally added to be alloyed, such that
the shrinkage initiation temperature of the nickel alloy particle is
moved to a high temperature.

[0075] However, in the case in which the internal electrodes are formed
using the conductive paste for internal electrodes formed of the nickel
alloy by adding two kinds of metals, the shrinkage initiation temperature
of the nickel particle of the related art may be moved to a high
temperature; however, the alloy component may react with the ceramic
component of the dielectric layer during the sintering process to
generate a disconnected portion in the internal electrodes, such that the
connectivity of the internal electrodes may be deteriorated, and a
dielectric rate of the dielectric layer may be deteriorated.

[0076] Meanwhile, in the present embodiment, the internal electrodes may
be formed by using the nickel powder and nano-scale nickel oxide, instead
of using the nickel alloy, in the conductive paste for internal
electrodes.

[0077] In this case, the internal electrodes may be shrinkage-controlled
to be the same level as the case of using the nickel alloy. In addition,
since there is no phenomenon in which the alloy component reacts with the
ceramic component of the dielectric layer during the sintering process,
the connectivity of the internal electrodes and the dielectric rate of
the dielectric layer may be prevented from being deteriorated.

[0078] As another method for solving the problem, the conductive paste is
prepared using two kinds of nickel oxide having different average
particle sizes, as a main component.

[0079] In this case, the nickel oxide is reduced under a reduction
atmosphere to thereby have excellent metallic properties; however, since
a content of nickel oxide is high, a change in volume generated in the
reduction process may deteriorate a densification of the internal
electrode.

[0080] Meanwhile, in the internal electrodes of the present embodiment,
since nickel is used as amain component and nickel oxide is partially
added as an additive, an excessive change in volume is not generated in
the reduction process, thereby implementing internal electrodes having
excellent densification after the sintering process.

[0081] Hereinafter, according to an embodiment of the present invention, a
conductive paste for internal electrodes is prepared, and the prepared
conductive paste is used to manufacture a multilayer ceramic capacitor.

[0082] The conductive paste for internal electrodes of the present
embodiment was prepared as a mixture of a nickel powder having an average
particle size of about 120 nm and a nickel oxide powder having an average
particle size of about 20 nm. The nickel oxide powders were weighted to
have contents of 1 part by weight, 3 parts by weight, 5 parts by weight,
7 parts by weight, 10 parts by weight, 11 parts by weight, 13 parts by
weight, 15 parts by weight, 17 parts by weight, and 19 parts by weight,
based on 100 parts by weight of the nickel powder, respectively.

[0083] Then, the conductive paste for internal electrodes was prepared by
adding an ethyl cellulose-based binder, a terpineol solvent, or the like,
to the mixture, and performing dispersive mixing with a three roll mill.

[0084] A conductive paste for internal electrodes of the Comparative
Example was prepared by the same method as described above, except that a
barium titanate powder is added thereto, instead of the nickel oxide
powder.

[0085] Then, the prepared conductive paste for internal electrodes was
dried and molded as pellets under the same pressure, by using a metal
mold. Then, a thermal mechanical analysis (TMA) was performed to measure
a shrinkage initiation temperature, connectivity of the internal
electrode, whether or not delamination was generated, and whether or not
a dielectric layer and the barium titanate powder were reacted with each
other, for each content of added materials. Results thereof are shown in
Table 1 below.

[0087] The shrinkage initiation temperature may be defined as a
temperature at which a shrinkage rate is 5%, and may be determined by the
TMA.

[0088] The connectivity of the internal electrode may be defined as a
ratio of "a real length of the entire electrode" to "an ideal length of
the entire electrode", that is, "the connectivity of the electrode=a real
length of the entire electrode/a length of the entire electrode".

[0089] The ideal length of the entire electrode may be calculated by
multiplying the length of a single layer of the internal electrodes and
the number of layers of the internal electrodes, and the real length of
the entire electrode may be a length in a remaining portion excluding a
disconnected portion of the electrode.

[0090] More specifically, the connectivity of the internal electrode may
be calculated by counting the number of pixels, and calculating a
relative ratio of the number of pixels, based on the high-powered
microscope image of a cross-section perpendicular to a surface at which
the internal electrodes are stacked.

[0091] If the connectivity of the internal electrode is high, the internal
electrode is formed without voids and high capacitance may be secured
therein, however, on the contrary, if the connectivity of the internal
electrode is low, an effective surface of the internal electrode forming
capacitance is decreased, and it may be difficult to form capacitance
therein.

[0092] Delamination refers to a phenomenon in which the internal
electrodes and the dielectric layers are separated from each other in the
multilayer ceramic electronic component. In the case in which
delamination is generated, electrical and mechanical characteristics of
the multilayer ceramic electronic component may be deteriorated.

[0093] Reactivity between the internal electrode and the barium titanate
of the dielectric layer refers to whether or not a material added to the
internal electrode reacts with the barium titanate present in the
dielectric layer. In the case in which the material added to the internal
electrode reacts with barium titanate present in the dielectric layer,
performance of the multilayer ceramic electronic component may be
deteriorated.

[0094] In the Inventive Examples, a standard of the shrinkage initiation
temperature was more than 700° C., generally having no problem in
reliability. In addition, a standard of the connectivity of the internal
electrode is 90% or more, which may generally secure appropriate
capacitance.

[0095] Referring to Table 1, in Sample 1, the Comparative Example, 10
parts by weight of barium titanate were added to the conductive paste for
internal electrodes, and the shrinkage initiation temperature was
850° C., higher than the standard of 700° C., and the
connectivity of the internal electrode was 95.3%, higher than the
standard of 90%. Delamination was not generated. However, there was a
problem in that the barium titanate added to the internal electrode
reacted with the barium titanate present in the dielectric layer.

[0096] In Sample 2, 3 parts by weight of nickel oxide were added to the
conductive paste for internal electrodes, and the nickel oxide added to
the electrode was not reacted with the barium titanate present in the
dielectric layer. However, the shrinkage initiation temperature was
600° C., lower than the standard of 700° C., the
connectivity of the internal electrode was 88.5%, lower than the standard
of 90%, and delamination was generated.

[0097] In Samples 3 to 8, 5 parts by weight to 15 parts by weight of
nickel oxides were added to the conductive paste for internal electrodes,
respectively, the shrinkage initiation temperatures were 770° C.,
815° C., 875° C., 880° C., 877° C., and
875° C., higher than the standard of 700° C.,
connectivities of the internal electrode were 92.1%, 94.0%, 95.2%, 95.3%,
95.1%, and 94.9%, higher than the standard of 90%, and delamination was
not generated. In addition, the nickel oxide added to the electrode was
not reacted with the barium titanate present in the dielectric layer.

[0098] In samples 9 and 10, 17 parts by weight and 19 parts by weight of
nickel oxides were added to the conductive paste for internal electrodes,
respectively, the shrinkage initiation temperatures were 882° C.,
and 885° C., higher than the standard of 700° C.; however,
the connectivities of the internal electrode were 89.8% and 85.9%, lower
than the standard of 90%, and delamination was generated.

[0099] Referring to FIG. 1, it may be appreciated that the shrinkage
initiation temperature of the conductive paste for internal electrodes is
increased until the amount of nickel oxide has a predetermined numerical
value or more, and then the shrinkage initiation temperature is decreased
at the predetermined numerical value.

[0100] The reason that the shrinkage initiation temperature is increased
is as follows. As the temperature is increased, the nickel powder
particles connected to each other are combined to be grown in order to
decrease a specific surface area thereof. When the nickel particles grow,
a nickel oxide is present between the nickel particles, such that a
probability of direct contact between the nickel particles is decreased,
as a result, the sintering initiation temperature is increased.

[0101] However, at the shrinkage initiation temperature according to an
amount of nickel oxide, an excessive amount of nickel oxide components
remains in a protrusion shape in a portion of the internal electrode
after the sintering process. Therefore, in the case in which the content
of nickel oxide is excessive, breakdown voltage (BDV) may be decreased,
and as the content thereof is increased, a change in volume in the
reduction process is increased to deteriorate the connectivity of the
electrode, and accordingly, there is a need to limit the content thereof.

[0102] Therefore, when analyzing the shrinkage behavior, the connectivity
of the internal electrode, and whether or not the delamination is
generated, the desired added amount of nickel oxide may be 5.0 parts by
weight to 15.0 parts by weight based on 100 parts by weight of nickel
powder.

[0103] Hereinafter, a method of manufacturing a multilayer ceramic
capacitor according to an embodiment of the present invention is
described.

[0104] Firstly, a plurality of first and second ceramic sheets may be
prepared.

[0105] A ceramic powder, a binder, a solvent, or the like, may be mixed to
prepare a slurry, and the slurry may be used to manufacture the first and
second ceramic sheets, having a μm level of thickness by a doctor
blade method. However, a method of manufacturing the first and second
ceramic sheets is not limited thereto.

[0106] Then, a conductive paste for internal electrodes may be applied to
at least one surface of the first and second ceramic sheets by a screen
printing method, a gravure printing method, or the like, to form first
and second internal electrodes 131 and 132.

[0107] Here, the first and second internal electrodes 131 and 132 may be
formed to be alternately exposed through both end surfaces of the first
and second ceramic sheets.

[0108] In addition, the conductive paste for internal electrodes may be
used by mixing a nickel powder, 5.0 parts by weight to 15.0 parts by
weight of a nickel oxide powder based on 100 parts by weight of the
nickel powder, and a small amount of an organic vehicle.

[0109] Then, the plurality of first and second ceramic sheets having the
first and second internal electrodes 131 and 132 formed thereon are
alternately stacked, pressurized in a lamination direction to compress
the first and second ceramic sheets and the first and second internal
electrodes 131 and 132 to each other, thereby manufacturing a ceramic
laminate in which the first and second internal electrodes 131 and 132
are alternately stacked.

[0110] Next, the ceramic laminate is cut for each region corresponding to
a single capacitor to be produced as a chip. Here, the ceramic laminate
may be cut so that one ends of respective first and second internal
electrodes 131 and 132 are alternately exposed through end surfaces of
the ceramic laminate. Then, the chipped laminate may be fired at
1000° C. to 1200° C. to manufacture a ceramic body 110.

[0111] Then, first and second external electrodes 121 and 122 may be
formed to be electrically connected to the first and second internal
electrodes 131 and 132 exposed to both end surfaces of the ceramic body
110, while covering both end surfaces of the ceramic body 110, whereby a
multilayer ceramic capacitor 100 may be manufactured. Then, plating
treatment may be further performed by using nickel, tin, or the like, on
surfaces of the first and second external electrodes 121 and 122.

[0112] As set forth above, according to embodiments of the present
invention, a conductive paste for internal electrodes having a shrinkage
initiation temperature (a temperature at which a shrinkage rate is 5% or
more) of 700° C. or more is prepared by adding a nickel oxide
thereto, and the prepared conductive paste for internal electrodes is
used to manufacture a multilayer ceramic electronic component, whereby
the generation of delamination and cracking may be suppressed to improve
the reliability of a product.

[0113] In the case of a multilayer ceramic electronic component according
to embodiments of the present invention, a shrinkage initiation
temperature of an internal electrode is increased to improve a difference
in stress between a ceramic sheet and the internal electrode, whereby an
agglomeration or disconnection phenomenon of the internal electrode may
be suppressed to improve the connectivity of the internal electrode. In
addition, since a ceramic component of a dielectric layer and a component
of the internal electrode may not react with each other to improve
withstanding voltage characteristics and dielectric characteristics.

[0114] While the present invention has been shown and described in
connection with the embodiments, it will be apparent to those skilled in
the art that modifications and variations can be made without departing
from the spirit and scope of the invention as defined by the appended
claims.